Help-wanted advertising is used by businesses when they are caught short and need workers quickly, as might be expected to happen when business activity picks up after a downturn. Table 14.4.8 shows a Box–Jenkins analysis of the help-wanted advertising index, while Figure 14.4.1 shows the data series with the Box–Jenkins forecasts.20
a. What kind of process has been estimated?
b. Which estimated coefficients (if any) are significant?
c. Based on the figure, would you be surprised if the help-wanted advertising index dropped to 15 in the year 1995?
d. Based on the figure, would you be surprised if the help-wanted advertising index rose to 120 in the year 1996?
e. The forecasts in the figure appear to level off after about 1995. Does this tell you that the help-wanted advertising index will stop changing from year to year in the future? Explain.